K-MC4 MONOPULSE RADAR TRANSCEIVER

Datasheet

Using VCO and IF Outputs

The IF amplifier provides two outputs per channel according to Fig. 1. These outputs are designed for

different requirements in processing radar signals. Both I (imaginary) and Q (real) mixer signals are

available. The I and Q signals are phase shifted by +90° or -90°, depending on the moving direction of

objects in range. I1 and I2 (and Q1 and Q2) signals are phase shifted by the object deviation from the

normal axis (refer to chapter Fig. 3 ).

FMCW generates an output signal even without an object in range because of the finite isolation

between transmitter and receiver path. This effect is called self-mixing and leads to a DC signal that

depends on the carrier frequency.

Example showing a single target:

Triangle VCO Amplitude: 8Vpp

Triangle period

Modulation depth

IF output freq.

I_AC and Q_AC outputs show a low

frequency caused by local carrier

feedthrough.

is often called beat frequency,

caused by a target at a distance of

about 3m.

Fig. 9: Ix and Qx Output FMCW signals with triangle VCO and df = 80MHz

Distance calculation

R

=

c

0

2

⋅

f

b

⋅

T

M

2

= 3m approx

For legend refer to Fig. 9

R

Range, distance to target

Please contact RFbeam Microwave GmbH for more informations on FMCW and also on FSK

applications

Ix and Qx IF Outputs

These outputs provide amplified low noise signals generated by doppler effects or FMCW. They

directly can drive ADC input stages of microprocessors or DSPs. Even with 10Bit of resolution only,

sensitive and relatively long range Doppler detections are possible. The outputs cover a frequency

range of 15Hz ... 300kHz.

12Bit ADConverters are recommended for higher sensitivity to get optimal resolution for filtering and

signal processing.

© RFbeam Microwave GmbH, Schuppisstrasse 7, CH-9016 St. Gallen

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